Cooking times are meant to be guidelines. Times include turning once, just past the halfway point in the grilling time.

Judging a fire's temperature
Red meats are usually cooked over a hot or medium-hot fire, while fish, poultry and vegetables usually do best over a medium fire.

Wait until the coals are covered in ash. Hold your hand about 5-inches above the grilling surface. If you can hold your hand there for 2-3 seconds, it's a hot fire, 4-5 seconds, a medium fire, and 6-7 seconds, a low fire.